Enhancing surface stability of LiNi0.8Co0.1Mn0.1O2 cathode with hybrid core-shell nanostructure induced by high-valent titanium ions for Li-ion batteries at high cut-off voltage

Abstract

Achieving a highly stabilized surface structure is the key to successfully enhancing the cycling stability of LiNi0.8Co0.1Mn0.1O2 (NCM) cathode material for Li-ion batteries at high cut-off voltage (4.5 V). In this work, we report a highly surface-stabilized NCM material via a high-valent titanium ion (Ti4+)-induced nanostructured hybrid surface with a core-shell structure. Consequently, the Ti-modified LiNi0.8Co0.1Mn0.1O2 cathode provides an excellent cycling stability with 92.3% capacity retention (100 cycles, 0.5C, 2.7–4.5 V). This proposed hybrid core-shell nanostructure prominently mitigates the surface structural degradations, continuous microcracking and parasitic reactions, effectively improving the surface structural stability. This efficient strategy provides a step towards further commercial application of the LiNi0.8Co0.1Mn0.1O2 material and can be extended to other layered cathode materials.